How much would be left on the table?

Costs vary as well as services performed. Call around and ask about this and there equipment.

If it is stingy or generous in readings.
What system they have.
Headers available for your engine? and if yours fit the dyno chassis.
Ask about how much to run test and tune the engine and how many runs you get at the cost.
Then how much more for additional runs.
If they have tuning kits for your carb
Time it takes on average.
Header swaping Ok?
Will they tune it?
Tell them your new to this and Ask everything you can think off.